Fluid pressure motor



June 18, 1968 R. R. HAGER 3,38

FLUID PRESSURE MOTOR Filed May 2, 1966 T0 VACUUM SOUECE INVENTOR.

ROBERT E. HfiGEE BY I (Ann-#18441 147'7'0ENEY 3,388,635 FLUID PRESSURE MOTGR Robert R. Hager, South Bend, Ind, assignor to The Bendix Corporation, a corporation of Deiaware Filed May 2, i966, Ser. No. 546,872 7 Claims. (Cl. 91-170) ABSTRACT F THE DISCLDSURE A fluid pressure motor construction having at least two movable walls arranged therein to be relatively movable, which fluid pressure motor may also comprise a partition member having provisions therewith for internally communicating the control chambers behind the movable walls and to communicate chambers in front of the movable walls so as to segregate the chambers internally of the motor without utilizing exterior conduits or passageways between a radially located axial flange of the partition and the housing of the motor.

This invention relates to a fluid pressure motor and more particularly to improvements in a motor of the aforesaid type having at least two independently or collectively operable movable walls for performing work.

Tandem type servomotors of prior art design have required that one construct different movable walls for operation therewithin as respects those which would be utilized in servomotors of a single wall type. This problem is more readily visualized when those skilled in the art to which this invention relates realizes the manual application of power in a single wall type and tandem wall type servomotors, as also would be the case in power applications, through a reaction means to translate a force transmitting member to yield output for the motor. In these prior art designs the tandem type units were constructed whereby the first and second movable walls within the housing are connected together. In these units the reaction means must be varied in order to arrive at a desirable proportioned feel. Therefore, the elements within the single wall type unit and the tandem wall type unit were essentially different.

It is a principal object of this invention to provide a movable wall design for a servomotor that is universal to both single and tandem type units.

It is a more detailed object of this invention to provide a tandem type unit having internal passage means which do not in any way utilize exterior passages or passages around the connection of the two shells of the housing together.

Other objects and advantages of this invention will appear from the following description of the drawing showing a cross section of a servomotor constructed in accordance with the principles of my invention.

With reference to the drawing there is shown a servomotor housing formed in two sections 10 and 12 that are joined together by a twist lock type connection as at 14. Shell 10 is provided with a central opening that locates a seal 16, and shell section 12 is provided with a similar central opening having a seal 18. Upon joining the two sections together, peripheral beads and 22 of rolling diaphragms 24 and 26 are compressed between an annular ring 28 and the radial abutting portions of the shell sections. The annular ring 28 is formed with an inwardly extending plate section 30 having a central opening aligned with the central openings of the housing sections in which a seal 32 is mounted.

The diaphragms 24 and 26 are each connected, respectively, to a solid center section or member 34 and 36 to form a front movable wall A and a rear movable States Patent 0 Patented June 18, 1968 wall B. Aflixed, as by welding at 38 to the front movable wall is a rearwardly projecting tubular member 40 that passes through the central opening in the partition 30 which passage is sealed by the seal 32. This tubular structure 40 encloses a passage having openings 42 through the movable wall A and radial openings 44 in its opposite end. Thus, a chamber 46 and a chamber 48 are in fluid communication.

Radially spaced from the central opening in the partition 30 is a tube 50 that is formed during the formation of the partition 30 to extend rearwardly therefrom. The movable wall B is formed to have an opening 52 aligned with the tube 50 and provided with forwardly extending bearing surfaces 54 for guiding the Wall E therealong. The tolerances of the opening 52 are to be held as close as possible. As the tube 50 is inserted through the opening 52 it distends portions 56 of the diaphragm 26 underlying the opening 52 in the plate 36. In other words, the diaphragm 26 is provided with an opening of lesser diameter than the tube 58 in order to bring about the stretching of the diaphragm about the tube. This will form a seal with respect to the passage of the tube 50 through the movable wall 13. As may be readily appreciated, the mold for the plastic plate 36 may be provided with the opening 52 by having a core of sutficient length in the mold therefor. Likewise by decreasing the length of the core forming the opening 52, one could readily manufacture a solid plastic movable wall B. While on the subject of the formation of the solid section of the movable wall B, it should be noted that there is also provided a forward boss 58 and a rearward boss 60 in which a reaction disc 62 and a valve poppet 64 are, respectively, located. Also an angled passage 66 communicates one side of the wall 36 to an internal valve chamber 68 controlled by the poppet 64 and a valve plunger 70. Finally the valve chamber is open radially by a passage 72.

In order to derive a work from the translation of the movable walls A and B there is provided a force transmitting rod '74 that is either formed with a ring 76 or groove to allow the reception of a snap ring thereto with a similar ring 78 being axially spaced forwardly on the rod 74 so that the wall A may move the rod 74 regardless of the wall B and that wall As release position is established. To the extreme right end of the rod 74 there is attached a head 80 that abuts the reaction disc 62. The tube 40 is of a length that will abut the head 89 of the rod 74. A return spring 82 between the housing section It) and the movable wall A forces the wall A to its rest position where the ring 78 is bearing upon a cupshaped structure or return stop 84 in the central opening of the housing section 10. In that the tube 40 bears upon the head 89, which in turn bears upon the disc 62, the movable wall B is also returned by the spring 82. If desired, rubber bumpers 86 may be employed on the rolling diaphragm 26 to reduce the noise of the returning movable wall B.

A push rod 88 is connected to the valve plunger 70 and to a brake pedal for operating the servomotor in a manner that is readily obvious to those skilled in the art.

In operation, the push rod 88 after overcoming valve return spring 89 will seat the poppet 64 on a vacuum seat 98, due to the action of the valve follow-up spring 91, both of the springs 89 and 91 bearing upon a snap ring or the like (not shown) extending radially from the push rod 88 beyond the broken section as viewed in the drawing, to close off vacuum supply from chambers 46 and 48 to chambers 92 and 4. Thereafter further movement of rod 88 removes plunger 70 from the poppet to introduce atmosphere to chambers 92 and 94 via passage 72 and tube 54). Rod 74 will then be translated. Reaction pressures on rod 74 will deform disc 62 to abut plunger 70 to lap the plunger and poppet after overcoming application force in rod 88.

It will readily be recognized by those skilled in the art that by using a foreshortened rear shell 12 and front shell 10, rear diaphragm 26 and rear plate 36 (plugged at 52) in their present configuration, a single diaphragm assembly is made.

Having described a construction for the invention, the true scope sought by these Letters Patent are in the following claims.

I claim:

1. A fluid pressure motor comprising:

a housing;

a first movable wall within said housing;

a second movable wall within said housing and axially spaced from said first movable wall;

a partition within said housing between said first and second movable walls, said partition including an annular ring affixed to said housing and a radially inwardly projecting wall having a central opening with a tube projecting therefrom towards and through said first movable wall to communicate a chamber between said housing and said first movable wall to a chamber between said partition and said second movable wall;

a control means for said motor having passage means including said tube for communicating at least two different pressure mediums to said motor to selectively suspend said first movable wall and said second movable wall in one pressure and create a pressure differential thereacross; and

a force transmitting rod operatively connected to said movable wall and said second movable wall at axially spaced points such that said first movable wall and said second movable wall can collectively or individually operate said rod.

2. A fluid pressure motor according to claim 1 wherein said first movable wall is characterized as a solid member united to said housing by a rolling diaphragm, said member having an opening providing a sliding fit for said tube and said diaphragm having an opening of lesser diameter than said tube such that said tube distends said diaphragm thereabout to provide a sliding seal for said opening in said member.

3. A fluid pressure motor according to claim 2 wherein said member is provided with forwardly projecting bearing surfaces guiding said first movable wall and preventing extrusion of the distended diaphragm between said tube and said member.

4. A motor in accordance with claim 1 wherein said second movable wall has a tubular structure atfixed thereto and projecting through said central opening to abut said first movable wall with a seal affixed to said partition about said central opening, said structure having an opening to a chamber in front of said second movable wall and a chamber between said first movable wall and said partition such that said tube and said structure form a part of the passage means of said control means 5. A motor in accordance with claim 1 wherein said and a chamber between said first movable wall and said partition such that said tube and said structure form a part of the passage means of said control means to the forward side of said first and second movable walls with the tube projecting from said partition member forming another part of said passage means of said control means to the rearward side of said first and second movable walls.

6. A fluid pressure motor according to claim 5 and further comprising:

a reaction means between said first movable wall and said head of said rod;

a return spring partially compressed between said housing and said second movable wall;

a sliding seal in an opening of said housing about said rod; and

a stop means including a plate and a second ring the former of which is located with respect to said housing and the latter of which is arranged on said rod to limit the action of said return spring forcing said walls rearwardiy in said housing.

7. A fluid pressure motor according to claim 1 wherein said passage means includes a rigid tubular structure affixed to said second movable wall and operatively connected to said first movable wall in addition to the tube projecting from said partition, said tube from said partition being slidably and sealingly extended through said first movable wall such that said rigid tubular structure communicates chambers in front of both said first and second movable walls and said tube communicates chambers to the rear of said first and second movable walls within said housing.

References Cited UNITED STATES PATENTS 2,989,035 6/1961 Stelzer 91-376 3,013,536 12/1961 Cripe 9l376 3,083,698 4/1963 Price et a1. 91376 3,205,785 9/1965 Holfer 92-48 3,289,547 12/1966 Kytta 91376 PAUL E. MASLOUSKY, Primary Examiner. 

